Propane blast kills mother and son at Vermont birthday gathering, three others hurt

A propane leak inside a home on Connecticut Trail in Granville, Vermont, triggered an explosion Saturday night that killed a 20-year-old man and his mother and left three other adults injured, according to the Vermont State Police. The blast happened during a birthday celebration at the house, off Post Office Hill Road in the sparsely populated Addison County town.

Troopers said the call came in at approximately 7:45 p.m. Liam O'Sullivan, 20, of Essex Junction, was pronounced dead at the scene. His mother, Sarah O'Sullivan, 46, also of Essex Junction, was rushed to Gifford Medical Center in nearby Randolph, a 25-bed critical access hospital that serves much of east-central Vermont, where she later died of her injuries, state police said in a follow-up release identifying the victims on Sunday.

What investigators found

A third resident, 69-year-old Sheila Hammond of Granville, was critically injured and remains hospitalized out of state, according to state police. Two additional adults suffered minor injuries and were treated at local hospitals. In total, five people were inside or near the home when it exploded.

The Vermont Department of Public Safety's Fire and Explosion Investigation Unit worked the scene through Sunday alongside the State Police Bureau of Criminal Investigations, the Field Force Division and the Victim Services Unit, with support from the department's Division of Fire Safety and the all-volunteer Granville Fire Department. Investigators concluded that the blast was accidental, caused by a propane leak inside the residence, and state police said the "preliminary investigation by VSP does not indicate the explosion was suspicious."

Autopsies performed Sunday, September 6, confirmed both O'Sullivans died of injuries consistent with the blast, according to the department's update.

A close-knit, isolated corner of Addison County

Granville is a town of roughly 300 residents tucked between the Braintree Ridge and the main crest of the Green Mountains, bordered by Warren to the north and Hancock to the south. Houses along Connecticut Trail sit well apart from one another, separated by woods and rolling terrain that residents say normally keeps the community out of the headlines.

Brenda Buker, a neighbor who lives downhill from the property, told WCAX that the force of the blast reached her house even though it is not visible from the scene.

"We heard a loud boom and stopped mid sentence, didn't know what had happened...It shook the house," Buker said, adding that she initially mistook the sound for fireworks she had heard earlier in the evening. "Granville very rarely hits the news, so this was unusual."

Some neighboring homes sustained broken windows from the force of the explosion, though Buker said her own house was undamaged. The Boston Globe and Vermont Business Magazine both reported that first responders described a chaotic scene as crews from multiple agencies converged on the rural road Saturday night and remained through the following day.

Who is affected

The O'Sullivans lived in Essex Junction, a village in Chittenden County in the northern part of the state, and had traveled south to Granville for what state police describe as a birthday celebration at the time of the blast. Family and friends of both victims are being supported by the State Police Victim Services Unit, which is typically deployed to assist relatives through the identification and notification process following a fatal incident.

Hammond, the critically injured Granville resident, remains hospitalized out of state in critical condition, according to police, who have not provided further updates on her status since Sunday's release. The two other adults treated for minor injuries have not been publicly identified, and it is not clear whether they were residents of the Connecticut Trail home or additional guests at the gathering.

Propane is a common heating and cooking fuel across rural Vermont, where many homes sit beyond the reach of natural gas pipelines and rely instead on delivered fuel stored in tanks outside the house or in a basement. State fire officials have not yet said whether the leak that caused Saturday's blast originated from an appliance, a storage tank, or interior piping, and a full technical cause-and-origin report typically follows weeks after an on-scene classification like the one issued Sunday. The Granville Volunteer Fire Department, like most departments serving Vermont's smaller towns, is staffed by unpaid local responders who train alongside their full-time jobs and who were among the first crews on scene Saturday night, working alongside state troopers on the darkened rural road.

What happens next

The Fire and Explosion Investigation Unit said it would continue processing the scene and would release further updates as the case proceeds, though no additional briefing had been scheduled as of Sunday evening. Vermont does not require a public inquest for accidental deaths, so any further findings are expected to come through additional State Police statements rather than a court proceeding.

No charges are anticipated given the accidental classification, and the investigation is expected to focus on documenting the failure point in the propane system for the state's fire-safety records rather than on criminal liability. State officials have not said whether the case will prompt any broader review of residential propane-safety practices in Vermont, though the Division of Fire Safety periodically issues public guidance on carbon monoxide detectors, tank maintenance and how residents should respond if they suspect a gas leak in the home.

For now, the loss has settled over two towns a mountain drive apart: Essex Junction, where the O'Sullivans lived, and Granville, where a Saturday-night birthday gathering ended in tragedy. Buker said neighbors were still absorbing what had happened as investigators worked through the weekend a short distance from her front door, describing a rural community unaccustomed to drawing statewide and now national attention.